This invention relates to an improved process for phosphate beneficiation. In particular, this invention relates to the use of an alkyl-substituted phenyl ether amine or its hydroxyalkylated derivative as a collector in the flotation of siliceous material from a mineral ore.
In the present commercial beneficiation of siliceous phosphate ores, a deslimed and sized phosphate ore is conditioned with and then floated by a fatty acid collector and fuel oil reagent in an aerated aqueous solution at a pH of at least about 8. This flotation process produces a low-grade phosphate concentrate containing from about 50 to 65 weight percent bone phosphate of lime (BPL). The low-grade concentrate from the aforementioned flotation is blunged with acid to remove fatty acid collector coatings and the phosphate is further concentrated by flotation of residual silica from the concentrate with a so-called cationic amine collector. Other mineral ores containing siliceous material, such as iron ore, are also beneficiated by flotation.
Polyethylenepolyamines (most frequently diethylenetriamine) condensed with a fatty acid are the current cationic amine collectors of choice in the art for the flotation of silica from phosphate. These condensates are effective collectors, but they are costly and only moderately active.